The glycineamide ribonucleotide transformylase enzyme (chicken liver) copurifies with formyl-methenyl-methylenetetrahydrofolate synthetase, AICAR transformylase (10-formyltetrahydrofolate: 5-amino-1-ribosyl-4-imidazoyl carboxamide-5'-phosphate transformylase) and serine transhydroxymethylase. We propose to carry out experiments designed to show the physical association of the complex including: 1) attempts to cross-link the neighboring proteins in order to show the close association of particular proteins; 2) labeling of the protein(s) with fluorescent probes and the measurement of fluorescent polarization in recombination experiments in order to demonstrate polarization changes indicative of saturation binding; and 3) sucrose density centrifugation studies in order to see whether the complex will sediment as an entity or whether the separate proteins will dissociate upon centrifugation.